Composite tuned circuit



Aug. 15, 1961 M. J. RELIS COMPOSITE TUNED CIRCUIT Filed Aug. 16, 1950 ATTYS the required electrical and mechanical stab its.

United States PatentO "ice 4 1, 96,610 SITE TUNED MP Matthew J. Relis, 190 '17n69-th n v'e mushingmff. Filed Aug. 16, 1950, Set. No. 179.,'8'41 7 Claims. ((31. 250-17) v (Granted under Title 35, U5. Code "(19 52), sec. 266) This invention relates generally to composite tuned cireuits,'ultra-'high frequency loop antennae, and the method of their manufacture. I

In the construction of resonant loops .it has heretofore been customary to resort to a circuit having, the term of a closed loop made up of a plurality of metal areu'a'te sectors between which are mounted strips of insulating material. The proper assembly of these component parts required additional mounting elements which added to the manufacturing difficulties of producing an antenna having type of one-piece, composite tuned circuit for use at ultra high frequencies.

It is a further object of this invention to provide a resonant circuit of unitary structure having high thermal and mechanical stability.

Another object of this invention is to provide a unitary structure wherein a plurality of resonantc'ircuits are provided having capacitive and inductive coupling therebetween.

.11 is an object of this invention to construct (a resonant circuit of the character described by a new and improved method.

A further object of this invention is to provide a method of construction of a unitary resonant circuit wherein the conductive portions of the circuit form a coating on the dielectric supporting member.

Another object is to provide a resonant circuit and :loop antenna of the character described which will be Simple and economical to manufacture with a high degree of reproducibility.

Other objects and .many of the attendant advantages of this invention will bereadi-ly appreciated as the same becomes better understood 'by'refercnce to the following detailed description when considered in connection with the accompanying drawings whercinr FIG. 1 is a diagrammatic view of an oscillatory circuit constructed in accordance with the preferred embodiment of the invention and illustrating the composite tuned circuit;

FIG. 2 is a cross sectional view of the composite tuned antenna taken on line 2-2 in FIG. 1;

FIG. 3 is a diagrammatic view of another oscillatory circuit including two coupled resonant circuits on a common dielectric supporting member, the resonant circuits and dielectric supporting member comprising a composite tuned circuit constructed in accordance with an alternative form of the present invention; and

FIG. 4 is a sectional view of the alternative form of the composite tuned circuit taken on the line 4-4 of FIG. 3.

Referring to the drawing for a more complete understanding of the present invention and moreparticularly to FIGS. 1 and 2, the structure of the composite tuned circuit disclosed therein comprises a dielectric base member 5 on which is placed a covering 6 of electrically conductive material. The ring 5 may be made of any suitable Patented Aug. 15, 1961 dielectric material such, for eiiample, as ceramic, plastic; or quartz; and the ring-surface 6 may be made of any suit able electrically conductive material such, for example, as copper or silver. in this specification the term ring is used to designate a clos'ed loop solid .havingcither arctl'ate or straighteline bounds or both. The term ringsurtacc'" designates the conductive layer on a closed loop solid. I

To insure proper placement of the covering 6 "on the base (member 5 "the conducting material may be applied an any suitable manner such, for example, as nycheniical deposition, electrochemical deposition, painting, or spraying. "Over a filmso applied, subsequent coats ma be applied by electroplating. In the case of vitreous n naf terials the base .member and covering may then be to obtain good adherence.

In the structure shown :in FIG; :1 and .FiG; 52 the in "ductance of the resonant circuit .is constituted by the separate segments 7 of the covering 6 and the capacitance is constituted by the gaps 8 adjacent thereto. Obviously high values of capacitance can be obtained by using :5; ring material of high dielectric constant. The gaps 8 are formed in said covering 6 to provide a plurality of the aforementioned inductive segments 7 by masking the base member 5 before the covering is placed thereon or by removing sections of the covering after "completely coating the base member. The width of the gaps or sun is usually small in comparison with the cross s'e'c'tionttl dimensions of the base member.

The resonant frequency of a tuned circuit constructed in accordance with the instant invention may be adjusted toany desired value over a wide :range by varying the shape, dimensions or the material used .fo'r'the base mem ber 6, and to a lesser extent by varying the width of the gaps 8. By varying the number of gaps, the capacitance can be changed while maintaining the inductance 'sdbstam tiall'y constant, thereby providing another means of trolling the resonant frequency.

The tuned circuit of the present invention be used in any of the conventional circuits where resonance is desired. impedance matching can 'be 'efiec'ted by varying the position of the gaps and the position of the connecting leads where they connect to the segments, and 13.0. corrncctions can usually be made at a neutral point near the mid-point of a given segment all of which are techniques in analogous circuits well .known to those skilled in the a t Referring to FIG. 1, a mod f utilizin the esonant circuit of the invention in an oscillator is shown. Ele tron discharge device '9 is operated as a conventional oscillator by connecting the high impedance of the resonant circuit bet-ween the grid 11- and plate :12. For this urpose connection can be made from these electrodes to adjacent sectors 7 of the resonant circuit, substantially as illustrated.

In FIGS. 3 and 4 is shown a view of the present invention wherein two coupled resonant circuits have been coated on a common dielectric supporting member 5. As hcreinbefore disclosed the resonant circuits are formed by a plurality of segments 7 separated by gaps 8. Two separate tuned circuits are obtained by providing annular slots 15 in covering 6 on opposite faces respectively of segments 7. The two resonant circuits when so constructed are concentric with respect to the center of the annular supporting dielectric member 5. When so constructed the circuit can be used in any conventional manner as coupled circuits such as, for example, the push pull tuned plate i 3 jacent to the plate connected sector of the other of the tubes.

Obviously many modifications and variations of the present inventionare possible in the light of theabove teachings. It is therefore to be understood thatwithin the scope of the appended claims the invention may be practiced otherwise than as specifically described.

The invention described herein maybe manufactured and used by or for the Government of the United States of America for governmental purposes without the payrnent of any royalties thereon or therefor. I i

. .What is claimed as new and desired to be secured by Letters Patent of the United States is:

. 1. A composite tuned circuit and loop antenna for high frequencies comprising, a closed ring of dielectric ma terial having a rectangular cross section, and a surface of conductive material contiguously surrounding substantially the entire surface of said ring and having. at least one gap therein whose dimension thereacross is small comparedto the lesser of thetwo dimensions forming the cross-sectional area of said ring, said conductive material constituting the inductance of the circuit, and the adjacent lengths of said material forming the gap constituting the -.j 2. A composite tuned circuit and loop antenna for high frequencies, comprising a dielectric mass formed in a closed loop, a pluralityof lengths of electrically conductive material coated on substantially the entire peripheral surface of said ring, a plurality of spaced transverse gaps in said material to form separate conducting portions, said portions and said gaps therebetween constituting the inductance and the capacitance of one resonant network, and a plurality of mutually spaced annular slots in said material to form a multiplicity of individual concentric resonant networks.

6. In an oscillator network circuit comprising an oscillator, anantenna and tuned circuit including a closed ring of dielectric material, a. thin coating of electrical conductive materialon substantially the entire surface of said dielectric, a plurality of mutually spaced transverse gaps in said conductive material to separate conducting portions thereof, said electrically conductive material constituting the inductance of said circuit, and the adjacent lengths of said material forming said gaps constituting the structural arrangement of the capacitance of said circuit, and circuit meanslfor interconnecting said oscillator, said antenna and tuned circuit. 7. A multiple resonant network circuit assembly comprising a closed, loop of dielectric material, a plurality of lengths of electrically conductive material contiguously structural arrangement of the capacitance of the circuit.

tive material mounted in spaced relation with respect to each other on'substantially the entire peripheral surface of said mass, said conducting material constituting the inductance of said circuit, and the adjacent lengths of said material constituting therebetween the structural arrange- 'ment of the capacitance of said circuit."

3. A composite tuned circuit and loop antenna for high frequencies, comprising a unitary ring of dielectric ma;- terial, an electrically conductive material thinly coated on substantially the entire peripheral surface of said ring :and having gaps in said material spaced at intervals around the ring to form separate conducting portions, said portions and said gaps therebetween constituting the inductance and the capacitance of the circuit. i

4. A composite tuned circuit and loop antenna for high frequencies, comprising an electrically nonconducting .closed ring, a plurality of isolated electrically conducting segments of metallic film adhering to substantially the entire peripheral surface of said ring and so disposed in .spaced relation thereon as to form gaps therebetween, said conducting segments constituting the inductance of the circuit, and said adjacent lengths of said conducting segments forming gaps therebetween constituting the strucztural arrangement of the capacitance of the circuit.

5. A multiple resonant network assembly comprising a closed ring of dielectric material, an electrically conducmounted in spaced relation with respect to each other on substantially the entire peripheral surface 'of said loop of dielectric material, said' electrically conductive material constituting the inductance of said circuit, and the adjacent lengths of said material therebetween constituting the structural arrangement of the capacitance of said circuit, and a plurality of'mutually spaced annular slots in said conductive'material to form concentric resonant networks on the inner and outer radii surfaces of the said dielectric loop. H

' References Cited in the tile of this patent UNITED STATES PATENTS 1,037,469 Goldberg .'I Sept. 3, 1912 1,741,477 Pfiffner Dec. 31, l929 1,994,76-7- Heintz Mar. 19, I935 2,166,750 ,Carter July 18, 1939 2,403,093 Lear July 2, 1946 2,405,123 Fyler Aug. 6, 1946 2,412,249 Brown Dec. 10, 1946 2,485,654 f Pickles Oct. 25, 1949 2,509,903 Brode May 30, 1950 2,575,377 Wohl Nov. 20, 1951 2,761,137 Van'Atta Aug. 28, 1956 FOREIGN PATENTS France Nov. 22, 1950 7 OTHER REFERENCES l Parker: Broadbanding Ring-Type," Tele-Tech, July 1949, pages 22-23. 

